Update as of 11:25 AM PST
Via BBC News, London
"The train recorder has been found and the information, including train speed, video of the accident, and the engineers steering attempts, is being downloaded. More than 240 people were on board Train 188, officials said.
NTSB representative Robert Sumwalt says that recorder will be "key to the investigation".
The train conductor was also injured in the crash, and is giving a statement to city police, says Mayor Nutter.
The train's engineer declined to give a statement to police and left the detectives'' office with a an attorney, the Philadelphia Inquirer newspaper reports."
I was traveling on a northbound Keystone about a month ago (Philadelphia - Trenton), cab car leading with 601 pushing